French Republican Calendar

During the Napoleonic wars most of Europe used the Gregorian calendar with the exception of Russia, which used the Julian calendar until the revolution of 1917. Between 1792 and 1805 France used what was known as the Republican Calendar. In this all the months were renamed and years began with the foundation of the Republic at An I. All months had 30 days except the 12th month, which had 35 or 36 on a leap year. The Republican year ran from September to August.